Today, all the speculation can be put to rest: Slingshot is here, for real this time.

Unlike Poke, Slingshot is not a direct Snapchat ripoff. "With Slingshot, we wanted to build something where everybody is a creator and nobody is just a spectator," Facebook said in a blog post announcing the launch.

That's right – lurkers aren't welcome on the app.

As with Snapchat, users can send photos or videos -- adorned with text or coloring, if desired -- that last up to 15 seconds with Slingshot. Each message can be viewed exactly once by the recipient before disappearing for good.

Unlike Snapchat, however, opening a message on Slingshot requires that you send a message of your own back to its sender. "Here’s the deal: friends won’t be able to see your shot until they sling something back to you," Facebook explained.

While it's good news that Slingshot isn't another straight-up Snapchat clone and while the intent is admirable, it's fair to wonder whether Facebook has overestimated our collective desire to share versus our collective desire to consume. After all, plenty of people use social networks to "lurk," spending most of their time checking up on other people's posts instead of posting themselves. For those types, being forced to respond to a message on Slingshot might be a tough sell.

Still, Facebook is determined to try. "[Venture capitalist] Fred Wilson once said that the cardinal rule of social networks is that 1 percent of people create content and 90 percent of people consume it," Slingshot designer Joey Flynn told the Verge, "and we want to flip that on its head."